Google Inc. is expanding into alternative energy in its most ambitious effort yet to ease the environmental strain caused by the company's voracious appetite for power to run its massive computing centres.

As part of a project announced Tuesday, the Internet search leader and its philanthropic arm will pour hundreds of millions of dollars into a quest to lower the cost of producing electricity from renewable energy sources such as wind and the sun.

If Google realizes its goal, the cost of solar power should fall by 25 to 50 per cent, co-founder Larry Page said in an interview.